unifyfs: dependency changes and new release (#20271)
unifyfs: dependency changes and new release (#20271)

This updates the UnifyFS packages to account for the latest v0.9.1
release.

Updates required and optional dependencies for the respective
releases.

Locks margo and mercury dependencies at specific versions while
integration with their latest versions is still in progress.
LLNL/spack,LLNL/spack,LLNL/spack,LLNL/spack,LLNL/spack